Added Emplace_hint file for unordered_map directory

unordered_map/emplace_hint.md

@@ -0,0 +1,44 @@
+# emplace_hint
+
+**Description :** 
+  * Inserts the key and its element in the unordered_map with a given hint. The hint provided does not affect the position to be entered. It inserts in the same order         which is followed by the container. 
+  * Only inserts unique key and avoids creating object for exisitng key.
+
+**Example** :
+
+```cpp
+/*
+    Author : parth_s
+    Date : 03/10/2022
+    Time : 02:12
+    Description : Implementation of emplace_hint method in an unordered_map in C++
+*/
+
+#include <iostream>
+#include<string>
+#include<unordered_map>
+
+int main() {
+
+    // initialize unordered_map container
+    std::unordered_map<int, std::string> mp;
+
+    // inserting elements in random order
+    mp.emplace_hint(mp.begin(), 3, "three");
+    mp.emplace_hint(mp.begin(), 1, "one");
+    mp.emplace_hint(mp.begin(), 2, "two");
+
+
+    // printing the map elements 
+    std::cout<<"The unordered_map elements are:"<<"\n";
+    std::cout<<"key\telement"<<"\n";
+
+    for(auto itr = mp.begin(); itr!=mp.end(); itr++){
+        std::cout<<itr->first<<"\t";
+        std::cout<<itr->second<<"\n";    
+    }
+
+    return 1;
+}
+```
+**[Run Code](https://rextester.com/AULM68896)**